Shortly after delivering the pair of tweets signaling his intent to seek a federal investigation into alleged vote fraud, Mr. Trump repeated his assertion to ABC’s David Muir in a Wednesday morning interview, telling his questioner the deceased and illegal immigrants constituted a bulk of the fraudulent voters.

“You have people that are registered who are dead, who are illegals, who are in two states. You have people registered in two states. They’re registered in a New York and a New Jersey. They vote twice. There are millions of votes, in my opinion.”

Despite skepticism among Democrats, many of whom angrily denounced Mr. Trump’s claim, some Republicans appeared leery of the president’s contention the November election was rife with fraud.

Although House Speaker Paul Ryan did not endorse Mr. Trump’s claim, the Wisconsin Republican told MSNBC an investigation may be required to “get to the facts.”

In contrast, House Oversight Committee Chairman Jason Chaffetz (R-Utah) declared there is no evidence to support the president’s assertion and stated he has no intention of conducting an investigation.

The call by Trump for a probe comes amid claims Trump family members and top White House advisers were registered to vote in multiple states.

According to election rolls, top adviser Steve Bannon is registered in New York and Florida; son-in-law Jared Kushner is registered in New Jersey and New York; White House Press Secretary Sean Spicer is registered in Virginia and Rhode Island; Treasury Secretary nominee Steve Mnuchin is registered in both New York and California; and daughter Tiffany is registered in New York and Pennsylvania.

Under law, it is not illegal to be registered to vote in two states; it is, however, illegal to cast ballots in more than one state in the same election.